There has been serious concern that microbial contamination of dental office water systems puts dental patients at risk of diseases. The problem of water contamination, especially when due to cross contamination from other patients, is greatest for patients with weak immune systems. Additionally, dental water can become contaminated from the water supply. More commonly, contamination results from growth of microbial biofilms on the inner surface of water lines. Such biofilms can include germs introduced from patients. Germs can slough off from biofilms as water passes through water lines. Thus, it is not uncommon for water coming out of dental hand pieces to have more than one million bacteria per milliliter while the water entering the dental lines has less than 100 bacteria per milliliter.
Existing systems do not remove microbial biofilms, do not provide failure warning are inconvenient, are expensive, require excessive dental labor and depend on perfect user compliance with manufacturers' instructions.